The area of a decagon is 200. If the side of a decagon is 4, what is the length of its apothem
+129839 A decagon is composed of 10 conguent isosceles triangles......so the area of one of these triangles = 200/10 = 10 square units
And we can find the apothem [ the height of one of the triangles = h ] thusly :
tan (72) = h/2 multiply both sides by 2
h = 2*tan(72) ≈ 6.155 units
